This disclosure relates to thermally stable polycarbonates, thermoplastic compositions thereof, and articles and uses thereof.
Aliphatic/aromatic polycarbonates typically have less satisfactory thermal stability due to pyrolytic elimination reactions involving β-hydrogens. EP0922722 A1 has reported that polyesters and polycarbonates with significantly improved thermal stability may be prepared from neoalcohols having no β-hydrogens, such as 2,2,4,4-tetramethylcyclobutane-1,3-diol (TMCBD). However, the high cost of TMCBD makes it impractical for many applications. Although neopentyl glycol (NPG) is a lower cost neodiol than TMCBD, and the bischloroformate of NPG has been prepared and converted into the corresponding BPA copolycarbonates, NPG tends to form cyclic carbonates which are generally undesirable. Moreover, NPG has a lower molecular weight, and requires a large amount of amine acceptor to allow incorporation into polycarbonates and copolycarbonates at effective levels.

There accordingly remains a need in the art for a polycarbonate, and a thermoplastic composition thereof, which is thermally stable, cost-effective, and has improved manufacturability characteristics, such as minimum cyclic carbonate formation and minimum amine acceptor requirement, among others.